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Creating a Multifunctional Composite Stator Slot Material System to Enable High Power Density Electric Machines for Electrified Aircraft ApplicationsIncreasing the power density and efficiency of electric machines (motors and generators) is integral to bringing Electrified Aircraft (EA) to commercial realization. However, power density and efficiency are not qualities that can be developed independently. At the heart of any electric machine are the conductors (usually copper) that carry current and generate magnetic fields. Increased power density means increased current density and increased joule heating in a smaller volume. To increase efficiency at the wire level means minimizing electrical resistance and hence power lost to joule heating. There are fundamental challenges with concomitantly increasing both power density and efficiency since the copper resistivity is very temperature sensitive at common electric machine operating conditions. Simple calculations of the linear increase in resistivity of copper as a function of temperature, reveals that a one degree Celsius increase in temperature results in a 0.39% decrease in efficiency. Conversely, a 20 degree Celsius decrease in copper temperature produces a 7.8% increase in efficiency. Therefore, improved thermal management concepts for electric machine building blocks such as stator winding are a priority for improving efficiency and power density. This paper proposing changing the view of component materials in the stator slots from individual components with singular functionality to a composite system where the components take on a multifunctional roles. In the composite framework, achievable material development goals are defined that together have maximum system impact on the thermal environment inside of high power density electric machines for aerospace applications.
Document ID
Acquisition Source
Glenn Research Center
Document Type
Woodworth, Andrew A.
(NASA Glenn Research Center Cleveland, OH, United States)
Jansen, Ralph
(NASA Glenn Research Center Cleveland, OH, United States)
Duffy, Kirsten
(Toledo Univ. Toledo, OH, United States)
Naghipour, Paria
(Ohio Aerospace Inst. Cleveland, OH, United States)
Shin, Euy-Sik
(Ohio Aerospace Inst. Cleveland, OH, United States)
Date Acquired
October 30, 2018
Publication Date
July 12, 2018
Subject Category
Composite Materials
Aeronautics (General)
Report/Patent Number
Meeting Information
Meeting: AIAA/IEEE Electric Aircraft Technologies Symposium (EATS)
Location: Cincinnati, OH
Country: United States
Start Date: July 12, 2018
End Date: July 13, 2018
Sponsors: American Inst. of Aeronautics and Astronautics
Funding Number(s)
WBS: WBS 533127.
Distribution Limits
Public Use Permitted.
thermal management
Electrified Aircraft
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